21 Apr
2016
21 Apr
'16
7:17 p.m.
Prior to the DEC Rainbow, Chrislin Industries was marketing the 11/23 with
vt103 as a desktop computer. This is a 3rd party vendor. Maybe they were
on to something...
Bill Degnan
twitter: billdeg
vintagecomputer.net
21 Apr
21 Apr
9:41 p.m.
william degnan wrote:
Prior to the DEC Rainbow, Chrislin Industries was
marketing the 11/23 with
vt103 as a desktop computer. This is a 3rd party vendor. Maybe they were
on to something...
Back around 1988, one of my customers had a few VT103
systems with just an RX02 for storage. A 3rd party
controller for an MFM drive (ST506 or DEC RD51) was
added since the DEC RQDX1 took too much power. There
was still sufficient power and room to place the
ST506 drive inside at the base of the VT103.
Prior to that point, I had a VT103 with just 256 KB
of memory and a DSD 880/8 which had an 8 GB hard
drive / RX03 floppy drive in an external box. So
there were other 3rd party solutions as well.
At one point, just to say that I had done so, I placed
a quad PDP-11/73 CPU along with 4 MB of memory, an ESDI
controller and a DHV11 with 8 serial ports into the
backplane of a VT103. I had to power the three 600 MG
hard drives from an additional PC power supply since
there was insufficient power from the VT103. But that
demonstrated that just a 4 x 4 Qbus backplane was
sufficient to run an extremely powerful PDP-11 system
using the VT103 as a base system with its own console
terminal. At one point, I heard that someone even
managed to make the first two slots ABCD which allowed
a MicroVAX II to be used instead, although a PDP-11/83
with PMI memory would have also been possible or a
PDP-11/93 could also have been used and one quad slot
would still have been available without the ABCD change
to the backplane.
These combinations could have been produced by DEC
and been years and technology ahead of the PC computer,
but that never happened. I have the impression that
the VAX was placed in a position of priority and most
development on the PDP-11 side which could compete with
the 32-bit VAX was restricted even though there were
still many applications where a 16-bit system was more
than adequate. DEC could have sold millions of VT103
systems.
Jerome Fine
10:31 p.m.
On Thu, Apr 21, 2016 at 9:41 PM, Jerome H. Fine <jhfinedp3k at compsys.to> wrote:
Sounds like a sweet little system... in 1987, I was using an 11/23 in
a BA11N (5.25"-tall rack-mount box) with RX02 and RLV11+RL01, so
packing all that, including the 5MB disk into a VT103 would have been
quite nice.
william degnan
wrote:
Prior to the DEC Rainbow, Chrislin Industries was marketing the 11/23 with
vt103 as a desktop computer. This is a 3rd party vendor. Maybe they
were on to something...
Back around 1988, one of my customers had a few VT103
systems with just an RX02 for storage. A 3rd party
controller for an MFM drive (ST506 or DEC RD51) was
added since the DEC RQDX1 took too much power. There
was still sufficient power and room to place the
ST506 drive inside at the base of the VT103. Prior to that point, I had a VT103 with just 256 KB
of memory and a DSD 880/8 which had an 8 GB hard
drive / RX03 floppy drive in an external box. So
there were other 3rd party solutions as well.
8MB? But otherwise, also nice.
At one point, just to say that I had done so, I
placed
a quad PDP-11/73 CPU along with 4 MB of memory, an ESDI
controller and a DHV11 with 8 serial ports into the
backplane of a VT103.
Now you're talking!
I had to power the three 600 MG
hard drives from an additional PC power supply since
there was insufficient power from the VT103.
Sure.
But that
demonstrated that just a 4 x 4 Qbus backplane was
sufficient to run an extremely powerful PDP-11 system
using the VT103 as a base system with its own console
terminal.
Yep. The biggest limitation was power, the second was limited number
of slots, so you needed small but powerful cards to make it
worthwhile.
At one point, I heard that someone even
managed to make the first two slots ABCD which allowed
a MicroVAX II to be used instead
Wow. That sounds like a fun but much bigger hack.
I have a VT103 (w/TU58)... I did set up a simple 11/23 in it once, but
I should see what I can do with a SCSI card...
-ethan
24 Apr
24 Apr
8:56 p.m.
Ethan Dicks wrote:
Prior to that
point, I had a VT103 with just 256 KB
of memory and a DSD 880/8 which had an 8 GB hard
drive / RX03 floppy drive in an external box. So
there were other 3rd party solutions as well.
8MB? But otherwise, also nice.
I have a VT103 (w/TU58)... I did set up a simple 11/23
in it once, but
I should see what I can do with a SCSI card...
If you are adding just a dual SCSI card, there is probably enough power
to also support an old 3.5" 50-pin SCSI drive. There will be more than
enough room to place the drive at the bottom of the VT103. I would also
make the SCSI cable long enough to support adding additional SCSI
drives (daisy chain) outside the VT103 so you can backup the internal
SCSI drive whenever you wish without having to get inside the VT103
each time. For my own VT103, I also added a switch and a power
plug to allow me to power the internal hard drive (SCSI or otherwise)
from an external PC power supply so that the VT103
power supply
would have a reduced load, especially at power-up when the load
is highest.
Jerome Fine
3005
days inactive
3009
days old
3 comments
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